Master slave communication system and control method for master slave communication system

Abstract

A master slave communication system capable of reducing a manufacturing cost is provided. The mater slave communication system includes a master node and a plurality of slave nodes having the same initial address. A communication between the master node and one slave node among the plurality of slave nodes is established by using the initial address set as an address of the one slave node. The address of the one slave node is changed into another address which has been transmitted from the master node to the one slave node through the established communication and is different from the initial address.

What is claimed is: 
     
       1. A master slave communication system, comprising:
 a plurality of slave devices, each of the plurality of slave devices including a register configured to store an initial address; and 
 a controller including at least one processor and being configured to: 
 supply an electric power to a first slave device among the plurality of slave devices; 
 establish a communication between the controller and the first slave device based on the initial address under a state where the first slave device is supplied with the electric power and a second slave device, different from the first slave device, among the plurality of slave devices is supplied with no electric power; 
 change, when the communication between the controller and the first slave device is established, the initial address stored in the register of the first slave device; and 
 supply an electric power to the second slave device after the initial address stored in the register of the first slave device is changed. 
 
     
     
       2. The master slave communication system according to  claim 1 , wherein
 the controller determines whether the communication between the controller and the first slave device is enabled based on a first change address predetermined for the first slave device. 
 
     
     
       3. The master slave communication system according to  claim 1 , wherein
 the controller establishes a communication between the controller and the second slave device based on the initial address under a state where the second slave device is supplied with the electric power, and 
 when the communication between the controller and the second slave device is established, the controller changes the initial address stored in the register of the second slave device. 
 
     
     
       4. The master slave communication system according to  claim 1 , wherein
 the controller establishes a communication between the controller and the second slave device based on the initial address under a state where the second slave device is supplied with the electric power and a third slave device, different from the first slave device and the second slave device, among the plurality of slave devices is supplied with no electric power, 
 when the communication between the controller and the second slave device is established, the controller changes the initial address stored in the register of the second slave device, and 
 the controller supplies an electric power to the third slave device after the initial address stored in the register of the second slave device is changed. 
 
     
     
       5. The master slave communication system according to  claim 4 , wherein
 the controller determines whether the communication between the controller and the first slave device is enabled based on a first change address predetermined for the first slave device, and 
 the controller determines whether the communication between the controller and the second slave device is enabled based on a second change address different from the first change address, the second change address being predetermined for the second slave device. 
 
     
     
       6. The master slave communication system according to  claim 1 , wherein each of the plurality of slave devices further includes a memory that stores the initial address. 
     
     
       7. The master slave communication system according to  claim 1 , further comprising a plurality of power supply lines that supply electric power to the plurality of slave devices, respectively. 
     
     
       8. The master slave communication system according to  claim 1 , wherein each of the plurality of slave devices further includes a slave processor. 
     
     
       9. A control method for a master slave communication system including a controller and a plurality of slave devices, each of the plurality of slave devices including a register configured to store an initial address, the control method comprising:
 supplying an electric power to a first slave device among the plurality of slave devices; 
 establishing a communication between the controller and the first slave device based on the initial address under a state where the first slave device is supplied with the electric power and a second slave device, different from the first slave device, among the plurality of slave devices is supplied with no electric power; 
 changing, when the communication between the controller and the first slave device is established, the initial address stored in the register of the first slave device; and 
 supplying an electric power to the second slave device after the initial address stored in the register of the first slave device is changed. 
 
     
     
       10. The control method according to  claim 9 , further comprising
 establishing a communication between the controller and the second slave device based on the initial address under a state where the second slave device is supplied with the electric power, and 
 changing, when the communication between the controller and the second slave device is established, the initial address stored in the register of the second slave device. 
 
     
     
       11. The control method according to  claim 9 , further comprising
 establishing a communication between the controller and the second slave device based on the initial address under a state where the second slave device is supplied with the electric power and a third slave device, different from the first slave device and the second slave device, among the plurality of slave devices is supplied with no electric power, 
 changing, when the communication between the controller and the second slave device is established, the initial address stored in the register of the second slave device, and 
 supplying an electric power to the third slave device after the initial address stored in the register of the second slave device is changed. 
 
     
     
       12. The control method according to  claim 9 , further comprising
 determining whether the communication between the controller and the first slave device is enabled based on a first change address predetermined for the first slave device. 
 
     
     
       13. The control method according to  claim 11 , further comprising
 determining whether the communication between the controller and the first slave device is enabled based on a first change address predetermined for the first slave device, and 
 determining whether the communication between the controller and the second slave device is enabled based on a second change address different from the first change address, the second change address being predetermined for the second slave device.